Fish Population control

[Andy41]

Hi Guys,

I'm in the middle of planning for a new pond, and would like your advice on fish control...

At first i was going to stock some Koi in addition to the goldfish i have now, but after reading around on here a bit i've found out that they eat the plants, so i've decided to stick to the Goldies.

My question though is how to control the breeding. In the pond i have now i started off with 3 Goldfish and now have about 100+ because they bred. The population seems to be stable now - i'm guessing they're eating any eggs? - but the new pond is going to be 8 times the size, and i don't want them breeding to large numbers.

I've read a bit about spawning mops, but i've no experience of them. My other idea was a fish that would eat eggs but i have no idea which one would be suitable.

Any ideas?

cheers,

Andy.

 

[addy1]

My pond in arizona is around 14k gallons, I put in some goldies a few shubunkins (10-12 years ago) and it has never gotten over populated. My pond keeper guy says the numbers are still stable, they must eat their eggs and young.

 

[Andy41]

Hi Addy,

How are you?

Interesting.... maybe the Shubunkins are eating the eggs? Nice looking fish though, i 'll try and get some for the new Pond

http://en.wikipedia.org/wiki/Shubunkin

cheers,

Andy.

 

[Nova]

I don't have a problem with the fish over populating in my pond either. I watch as a group of fish spawning are followed by a group of fish eating the freshly laid eggs and when I had seen a group of fry they don't last. For all the eggs being laid and fish hatching very few survived.

 

[fishin4cars]

Come borrow my owl, he will keep it check for you! LOL No really, ponds have a way of checks and balances, the more fish in the pond the more likely to eat eggs and fry. the fewer the fish the more likely fry, one reason is when they are breeding you have two fish or maybe a third male that we be actually breeding with the female, everyone else doing the chasing is eating and having a feast. So the chances of them getting eaten by one or two chasers is far less likely than if there are seven, eight even, ten chasers. another little guy that does a great job at keeping them in bay are mollies, IF your water stays above 50 degrees, they like salt like Goldies and Koi, they may slightly nibble plants but then again, Goldfish will too. never enough damage to kill them but they like plant matter in their diet. If all else fells, Grab a big net and scoop some out for a friend, or another pond. LOL Oh did I say another Pond? Yep I did, Ponding addict talking there! LOL Good luck! I've yet to ever get too many babies, but maybe that day will come. HeHeHe

 

[j.w]

If you don't feed your goldfish you will not have an overpopulation and they do get enough to eat w/o us feeding them. It's just fun to feed them and have them come to us. Also if you feed them just don't feed them all the time and they will take care of the population somewhat. I didn't feed mine for several yrs and they were just fine eating whatever bugs, worms that entered the pond. Now I feed them but only once a day in the warmer weather and just a little :twisted:

 

[addy1]

I don't think my renters feed them, I did random feeding, worked many long hours when I was there. so that may be why they did not over populate.

 

[uconnhusky2]

Found this thread which addresses a concern of mine. I had a self made fish pond, about 1000 gallons. My common goldfish bred consistently until I introduced Koi. I believe the Koi then ate the eggs as the fish stopped reproducing. However I moved and brought my fish with me. I lost some and by the time I decided to use a natural pond (8 feet deep at the center, about 50x70 feet in size), I had three koi left and about 15 goldfish. After two months the koi were no longer around, I assume captured by a predator, maybe a blue heron. However when I thought my goldfish were gone (and these trace back to four initial fish bought in 2002), I discovered I had about 35. Then by September I could count just over 100. Again as fall arrived I didn't see many and thought they were eaten. Low and behold on a rare 60 degree day before Christmas here in CT, they surfaced and I now had over 200 goldfish that I could see and count. While the pond is big enough, and in spite of allowing them to fend for themselves (no feeding), I'm wondering how to control the population. At this rate I could easily have over 2000 fish by next summer. If Koi did control them I would go with that, but not when I can't protect the Koi from being eaten. I'm afraid of reaching the point that I'll be skimming dead fish from the water.

I see here that they may reach the point of eating their own eggs and they will self control the population. Can I count on that? I love the fish, I am afraid of them attracting wildlife, but more afraid of dealing with quantities of dead fish decaying in my pond.

 

[MitchM]

uconnhusky2, this natural pond that you transferred your goldfish to, is there a possibility that it's waters could spill into natural waterways?
If so, then you may have a more serious problem on your hands from local fish and wildlife authorities.
If this natural pond is more like an isolated dugout, then I would look into getting some fish from a local fish hatchery that could control the goldfish population.


.

 

[uconnhusky2]

MitchM
No it is man made. It catches run off and holds it. It can lose four to six feet of water in dry weather like last fall. The only run off is overflow on adjacent land when it reaches the top. The fish have nowhere to go unless eaten. We do have heron, not sure if coyote feed on fish. I've also heard fisher cats and have pics of at least one feral cat that roams the area. It's an isolated area on the back of my 7 acres and I have a wildlife camera set up there.

 

[uconnhusky2]

Here's a picture of part of the pond with some of the fish in December.

 

[MitchM]

Glad to hear that it's isolated.
Goldfish are pretty tough though. As long as you're not feeding them, the population will balance out.
What about introducing local frogs and turtles? I'm not sure about your climate and environment, but I don't feed my pond fish either, and I notice a rise and fall in various insects that feed on the smaller fish.
It all seems to balance out in the end.

 

[uconnhusky2]

No turtles but many frogs though that hasn't seemed to have an effect. I guess I'll hope they self control. My biggest issues with my lined and filtered ponds were herons which I controlled with nets and at the population peak of about 100 in the smaller pond we had a heat wave and the heat and oxygen loss caused about half to die. Then the koi were added, grew to about 18" and no more goldfish babies. But koi are attractive targets, big and visible and slow. I don't want to raise them to a decent size to lose them and no way to net a retention pond of this size. Thanks for your replies Mitch.

 

[MitchM]

You're welcome.

What about adding some marginal plants around the pond perimeter which would give the goldfish an area in shallow water to hang out in, at the same time making them more available to herons?
I don't have herons here, so I'm not familiar with their behaviour. Just a suggestion.

.

 

[John O]

This summer I bought a lot of plants and vegetation for our 1800 gallon pond but by now, the two big koi most of it. There can be no other explanation. The two large bog grass plants in floating islands are there but the water lilies vanished as well as a lot of bottom grass plants. The pond had been covered by hyacinth and that makes great cover but until April, that is not possible. The bridge that spans the pond gives cover as well as the grass and another plant that spreads quickly. I don't recall it's name but it has yellow flowers when spreading. I am going to have to visit a local pond nursery for some advice.